Wi-Fi Calling: UK Mobile Network & Handset Compatibility

Wi-Fi Calling allows you to make and receive phone calls even when a mobile signal isn’t available.

In the UK, seven mobile networks currently offer Wi-Fi Calling support. The technology allows you to stay connected in places where a regular mobile signal isn’t available. You’ll be able to make and receive phone calls over wi-fi in the normal way, using your regular phone number and regular price plan.

To benefit from Wi-Fi Calling, you’ll need to have a compatible handset and price plan. At the time of writing, Wi-Fi Calling is available to customers on BT Mobile, EE, iD Mobile, O2, Sky Mobile, Three and Vodafone. However, individual networks have limitations on which price plans they support (e.g. only making it available to Pay Monthly customers) and handset compatibility may also vary (especially on Android-based smartphones).

In this article, we’ll tell you everything you need to know about Wi-Fi Calling in the UK. We’ll start by discussing how the service works, before looking at how Wi-Fi Calling is implemented on different mobile networks. Finally, we’ll look at the limitations of the technology and alternative solutions if you’re not able to benefit from Wi-Fi Calling.

What is Wi-Fi Calling?

Wi-Fi Calling is a fairly new technology that allows you to make and receive phone calls using only a wi-fi internet connection (it’s also known by its technical name of VoWiFi). Your wi-fi network will typically need to have a minimum speed of at least 1-2Mbps.

The technology means you’re finally able to use your phone as normal in places with patchy coverage or no mobile signal (for instance, in rural areas, basement flats and on the London Underground).

The key difference between Wi-Fi Calling and other app-based solutions such as WhatsApp, Facebook Messenger and Skype is you’re able to use your normal phone number and price plan, with no need to use or install additional applications. Because of this, it’s best suited as a solution for improving coverage and for making regular UK phone calls already included in your plan. For calling abroad, traditional app-based solutions such as WhatsApp and Skype continue to offer a better solution in most cases.

Wi-Fi Calling: By Network

Wi-Fi Calling is currently available to the following customers on BT Mobile, EE, iD Mobile, O2, Sky Mobile, Three and Vodafone:

BT Mobile

On BT Mobile, it’s possible to set up Wi-Fi Calling on any type of plan (including SIM Only, Family SIM & Pay Monthly) providing you have a compatible device with the latest software. At present, BT says the service is designed to work on the iPhone 5s or later, on the Samsung Galaxy S9, S9+ and A8 (2018).

If you’re using an iPhone, you’ll need to have iOS 11.2 or later, as well as the iD Mobile carrier settings version 31.1 or later. You can check this by going to Settings > General > About on your iPhone whilst connected to the iD network.

If you have an Android-based smartphone, your device will typically need to be running on O2-provided firmware. In most cases, this means your handset will need to have been purchased directly from O2. However, it will also work on certain handsets purchased from a third-party provider.

Three

Three’s Wi-Fi Calling service is called inTouch.

Three offers a wi-fi calling service to all of their customers, including both Pay Monthly and Pay As You Go customers. To use the ‘inTouch’ wi-fi calling functionality, you’ll need a compatible smartphone with the latest software updates installed:

If you have an Android smartphone that isn’t purchased directly from Three, or if you have another smartphone that isn’t listed above, it might be possible to use the Three InTouch application to add wi-fi calling to your device (available on the iPhone 4 and later, and smartphones running Android 4.0+).

Vodafone

On Vodafone, it’s possible to use Wi-Fi Calling if you have a compatible price plan and handset. You’ll need to be a Pay Monthly customer on a Red Extra, Red Entertainment, Red or Red Value plan. Handsets currently supported by the service are:

In order to activate the service, you’ll need to log in to My Vodafone. Go to Settings and Extra > Calling options and toggle the Wi-Fi Calling option to On. Once you’re connected to the Vodafone Wi-Fi Calling service, the network name on your handset will show as “Vodafone Wi-Fi”.

Drawbacks & Limitations

There are a number of key drawbacks and limitations associated with Wi-Fi Calling:

Wi-Fi Calling only works when you’re inside the UK.

You can only use Wi-Fi Calling when you’re in the UK. At present, all UK mobile networks restrict things so you’re only able to use Wi-Fi Calling when you’re inside the UK. Although there’s no technical reason why Wi-Fi Calling couldn’t work abroad, there’s a fear from the mobile networks this will cannibalise their international roaming revenues (as Wi-Fi Calling could potentially allow you to bypass these charges).

Phone calls might drop when you move out of the wi-fi coverage area, unless your phone also supports 4G Calling. If your phone or price plan doesn’t support 4G Calling, you’ll find phone calls dropping every time you leave the range of your wi-fi network. This could also happen if there are connectivity problems on wi-fi (e.g. if heavy congestion causes the speed to drop). It isn’t possible for a Wi-Fi Calling phone call to seamlessly transfer from wi-fi to 2G or 3G.

Some network features aren’t compatible with Wi-Fi Calling. If you’re connected to Wi-Fi Calling, you may not be able to change certain settings (e.g. call waiting, call forwarding or withheld number settings). Some network features may also stop working e.g. call recording and conference call features.

Android smartphones may require network-specific firmware. If you’re using an Android smartphone on certain mobile networks like EE and O2, it will only be compatible with Wi-Fi Calling if you have the right network-specific firmware. In practice, this means your handset will need to have been purchased directly from the mobile network (as opposed to being purchased SIM-free or from retailers like the Carphone Warehouse).

Wi-Fi Calling will use your regular mobile network price plan. Wi-Fi Calling will always use your regular price plan. While this means you’ll be able to use the inclusive minutes on your plan, it could also mean things like international calling are prohibitively expensive.

Alternatives to Wi-Fi Calling

At present, Wi-Fi Calling is only available to customers with a compatible handset and price plan on selected mobile networks (BT Mobile, EE, iD Mobile, O2, Sky Mobile, Three and Vodafone).

If you’re looking to save money on phone calls (e.g. whilst travelling abroad or calling internationally), it might be worth using an app-based solution instead. For instance, applications such as WhatsApp, Facebook Messenger and Skype allow you to call people in other countries outside of your regular price plan.

Your Comments
37 so far

Di Pinnellsaid:

Please note: Three’s Three-In-Touch app ceased today 15th May 2019. They abandoned it explaining that most phones come with wifi-calling now (!) but only guarantee that this will work on phones they supplied. They are providing me with a box to plug in to my router to simulate their ex-App. Motorola said their phones are capable of wifi calling, but only if the service provider enables it. This makes it almost impossible to choose a new phone if you have a SIM-only contract and are used to choosing your own phone and buying it from Amazon or whoever. Sounds a bit unfair: if they improved signal coverage we wouldn’t have the problem in the first place!!!

Eddie Jreplied:

I agree. I’ve just bought a Moto G7 Power (3 Pay As You Go Sim), which doesn’t have the Wifi calling setting available. I’ve contacted Motorola who ensure me that the phone supports wifi calling and 3 insist that their sim will enable wifi calling if the phone has wifi calling enabled.

So everything looks like it should work, but still no wifi calling! It looks like I may be doing a lot of phone returns until I find one which works.

Also my Wife’s Huawei P20lite does provide wifi calling with a 3 Pay As You Go Sim, but given Huawei’s current problems I don’t want to go down that route.

Dave Robertsonsaid:

I bought a OnePlus 6 from o2 in June, and I switched from Three to EE in the last month.

I was very pleased to see that the phone seems to support WiFi calling natively, which is surprising because it doesn’t have any carrier firmware (and if it did, it’d be O2’s, since I got it from them).

It doesn’t work on the tube WiFi though, unlike my Pixel 2 XL. I assume that’s down to a lack of “official” support.

John Haworthsaid:

Bought a Nokia 5 at car phone warehouse with a £10 ee pay as you go SIM which I did not activate. Put in my bt SIM only card switched on Wi-Fi calling and now I get ee Wi-Fi calling almost all the time at home because of the very poor signal and it is just like having 5 bars, it’s wonderful. My phone tells me it is connected to ee wifi calling and not bt Wi-Fi calling even though it is a bt sim.

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About Ken

My passion is helping people to get the most out of their mobile phone. I've been blogging at Ken's Tech Tips since 2005.

Aside from writing about mobile technology, I have an interest in software development, digital marketing and physics. Outside of the blog, I work with numerous technology companies helping them to market their product to consumers. Find out more.